using System;
using System.Collections.Generic;
using System.Linq;
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Audio;
using Microsoft.Xna.Framework.Content;
using Microsoft.Xna.Framework.GamerServices;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using Microsoft.Xna.Framework.Media;

namespace Cam
{
    /// <summary>
    /// This is the main type for your game
    /// </summary>
    public class Game1 : Microsoft.Xna.Framework.Game
    {
        GraphicsDeviceManager graphics;
        SpriteBatch spriteBatch;
        private Screen screen = Screen.GameScreen;
            //saves the old screen
        Screen OldScreen= Screen.MenuScreen;

        private IScreen SetScreen = new Cam.GameScreen();
       

        public enum Screen
        {
            GameScreen,
            HelpScreen,
            LogoScreen,
            MenuScreen

        }


        public Game1()
        {
            graphics = new GraphicsDeviceManager(this);
            this.IsMouseVisible = true;

            Content.RootDirectory = "Content";
            
        }

        /// <summary>
        /// Allows the game to perform any initialization it needs to before starting to run.
        /// This is where it can query for any required services and load any non-graphic
        /// related content.  Calling base.Initialize will enumerate through any components
        /// and initialize them as well.
        /// </summary>
        protected override void Initialize()
        {
            // TODO: Add your initialization logic here
            //set the backbuffer wdiths
            Globals.Globals.Screen_Height = graphics.GraphicsDevice.Viewport.Height;
            Globals.Globals.Screen_Width = graphics.GraphicsDevice.Viewport.Width;
            Globals.Globals.CameraOffset = new Vector2(Globals.Globals.Screen_Width/2,Globals.Globals.Screen_Height/2);
            Globals.Globals.Graphics = graphics.GraphicsDevice;
            base.Initialize();
        }

        /// <summary>
        /// LoadContent will be called once per game and is the place to load
        /// all of your content.
        /// </summary>
        protected override void LoadContent()
        {
            // Create a new SpriteBatch, which can be used to draw textures.
            spriteBatch = new SpriteBatch(GraphicsDevice);

            // TODO: use this.Content to load your game content here
        }

        /// <summary>
        /// UnloadContent will be called once per game and is the place to unload
        /// all content.
        /// </summary>
        protected override void UnloadContent()
        {
            // TODO: Unload any non ContentManager content here
        }

        /// <summary>
        /// Allows the game to run logic such as updating the world,
        /// checking for collisions, gathering input, and playing audio.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Update(GameTime gameTime)
        {
         
        
            //update the screen
            screen = SetScreen.Update(gameTime);

            //switeches the screen if there not the same
            if (OldScreen != screen)
            {
                switch (screen)
                {
                    case Screen.GameScreen:
                        SetScreen = new Cam.GameScreen();
                        SetScreen.Load(Content);
                        break;
                    case Screen.HelpScreen:
                        SetScreen = new Cam.Help();
                        SetScreen.Load(Content);
                        break;
                    case Screen.LogoScreen:
                        SetScreen = new Cam.LogoScreen();
                        SetScreen.Load(Content);
                        break;
                    case Screen.MenuScreen:
                        SetScreen = new Cam.Menu();
                        SetScreen.Load(Content);
                        break;
                       
                    default:
                        break;
                }
                OldScreen = screen;
            }
            // Allows the game to exit
            if (GamePad.GetState(PlayerIndex.One).Buttons.Back == ButtonState.Pressed)
                this.Exit();

            // TODO: Add your update logic here

            base.Update(gameTime);
        }

        /// <summary>
        /// This is called when the game should draw itself.
        /// </summary>
        /// <param name="gameTime">Provides a snapshot of timing values.</param>
        protected override void Draw(GameTime gameTime)
        {
            GraphicsDevice.Clear(Color.CornflowerBlue);
            spriteBatch.Begin(SpriteSortMode.Deferred, BlendState.AlphaBlend, null, null, null, null, Camera.GetMatrix());
            // TODO: Add your drawing code here
            SetScreen.Draw(spriteBatch);
            //draw the screen
            spriteBatch.End();
    
            base.Draw(gameTime);
        }
    }
}
